| 511-300/A Seat | |
| Early BSA A7/10, GS, Leighton (Narrow) | |
| Bottom Length: | 26-1/4" |
| Bottom Width (at widest point): | 11-1/2" |
| Top Length (beading to beading): | 25" |
| Thickness/Height (midpoint): | 3-3/4" |
| 511-300/A Seat | |
| Early BSA A7/10, GS, Leighton (Narrow) | |
| Bottom Length: | 26-1/4" |
| Bottom Width (at widest point): | 11-1/2" |
| Top Length (beading to beading): | 25" |
| Thickness/Height (midpoint): | 3-3/4" |